Unfortunately, that is more or less the market price for BZs nowadays. I saw one sell in HK for AU$5000 (it's MISB though). Sold within 5 hours of being put up in a store front.
For the one on auction, I'd pay $1500 to $1700 tops. Don't think I'd pay over $2000. It's in really great condition and I think mintier and more unused than mine (shameless plug, ahahahaa).![]()